Presentation on theme: "Corn (Zea mays L.) Leaf Angle and Emergence as Affected by Seed Orientation at Planting Guilherme Torres, Jacob Vossenkemper, William Raun, John Solie."— Presentation transcript:
1 Corn (Zea mays L.) Leaf Angle and Emergence as Affected by Seed Orientation at Planting Guilherme Torres, Jacob Vossenkemper, William Raun, John Solie and Randy TaylorDepartment of Plant and Soil SciencesDepartment of Biosystems and Agricultural EngineeringOklahoma State University
2 Introduction Increasing Yield Plant population (Cox 2001). 80,000 and 116,000 plants/haReducing row spacing (Lutz et al. 1971).40, 30, and 15 inchesLeaf architectures of modern corn hybrids (Stewart et al. 2003).
3 Rationale Stinson and Moss (1960) When soil moisture and nutrients are satisfactory light can be the primary ecological factor limiting grain yields.Peters (1961)Systematic orientation of corn leaves using seed planting techniques provides means for capturing more sunlight and more efficient soil shading.Donald (1963)Leaf geometry and its effects on light distribution with crop and levels of photosynthesis offer potential strategies for improving production efficiency.Stewart et al. (2003)Leaf architecture of modern corn hybrids can optimize light interception to increase grain yield.
4 Rationale cont.More homogenous corn stands have 1. Less interplant competition, increased light interception, reduced weed pressure, (quicker canopy closure). 2. Ability to potentially increase seeding rates while substantially increasing corn grain yields. 3. Reduce seeding rates and maintain grain yields.
5 Light Interception Pendlenton et al. (1967) 35 % yield increase in corn when aluminum reflectors were used to provide additional light to the middle and lower leavesReichert et al. (1958) and Stinson and Moss (1960)Reductions in grain yield when artificial shading was used to reduce available lightSujatha et al. (2004)Found that in irrigated production systems, prostate leaf architectures from the corn hybrids could assist in integrated weed management with the potential to decrease herbicide rates.
6 Emergence Hodgen et al. (2007) Daft et al. (2008) Martin et al. (2005) Found that if corn plants are delayed by as little as four days, the yield depression of that individual delayed plant was as much as 15 percent.Daft et al. (2008)Heterogeneous corn plant stands can lead to over application of fertilizers, pesticides and supplemental irrigation because these late emerging plants compete for nutrients, and produce little to no yield.Martin et al. (2005)Homogenous corn plant stands and emergence may decrease plant-to-plant variation and could lead to increased grain yields.
7 ObjectiveIdentify which seed placement and arrangement could result in plant architecture with leaves orientated perpendicularly to the row and understand the effect of seed position on emergence.With-rowLeaf orientationAcross-row
8 Greenhouse Trials Materials and Methods Planted 2.5 cm deepMedium flats10 seeds per treatmentRedi-earthAdobe Illustrator CS4 softwareEmergenceLeaf angleAnalysis of varianceFrequency distributionAngle ranges (%)
9 Leaf angle Deviation from the corn row Between 0° and 90° Angle ranges 0 ° to 30 ° (with-row)30 ° to 60 °60 ° to 90 ° (across-row)Leaf symmetry
12 Frequency distribution Results (E1)Source of variationdfLeaf AngleEmergenceFrequency distributionReplication9**NSTreatment5plants with leaf angle between 0° and 30° degreesplants with leaf angle between 60° and 90° degreesMSE58313.580.12Treatment meansNMeanStandard deviationDegrees%157.028.24.30.5022.266.721018.74.80.420.070.0367.814.45.00.0010.090.0467.218.418.8126.96.36.19980.0620.616.9SED7.920.15C.V.367
13 Frequency distribution Results (E2)Source of variationdfLeaf AngleEmergenceFrequency distributionReplication9NS**Treatment12plants with leaf angle between 0° and 30° degreesplants with leaf angle between 60° and 90° degreesMSE105413.650.12Treatment meansNMeanStandard deviationDegrees%151.018.06.60.5122.244.421065.6188.8.131.520.080.0347.419.37.320.070.0462.427.86.330.040.0529.013.06.00.0010.0631.5184.108.40.20660.0745.623.16.9848.023.77.162.014.90..3177.868.919.490.01157.019.77.055.654.822.45013RANDOM54.921.8SED9.090.15C.V.39
14 Frequency distribution Results (E3)Source of variationdfLeaf AngleEmergenceFrequency distributionReplication9NSTreatment7**Hybrid4*plants with leaf angle between 0° and 30° degreesplants with leaf angle between 60° and 90° degreesMSE309311.770.26Treatment meansNMeanStandard deviationDegrees%15062.617.26.41.058.072.024551.4220.127.116.112.260.0364.718.104.22.1684.076.04938.817.06.81.1046.920.4547.818.17.00.5532.038.0666.314.170.7586.020.80.7250.08RANDOM48.817.80.992848.0SED7.890.23C.V.33
15 Discussion Fortin and Pierce (1996) Bowers and Hayden (1972) Found that random orientation of seed resulted in random ear leaf azimuthsBowers and Hayden (1972)Flat orientation (hypocotyl up) consistently had better emergence (beans)Patten and Van Doren Jr. (1970)Proximal end of the seed down resulted in earlier more complete emergence with more seedling growth
16 Field Trial – Materials and Methods RCBDRow Orientation: North-SouthRow spacing: 30 inchesLight interception, V10 and R1(LI-1400)Grain yield at harvestCorn HybridsProstate leaf pattern - P0902HRUpright leaf pattern - P1173HR(within incomplete factorial arrangement)Seed OrientationUpright, caryopsis pointed down, parallel to the rowLaying flat, embryo up, caryopsis pointed perpendicular to the rowRandomPlant Population (in thousands of seeds / acreIrrigated trial – 20, 30 and 40Dry land trial -15, 20 and 25Row orientation
22 Discussion Toler et al. (1999) Differences in light interception between leaf orientations decrease with maturity.No differences were found in plant population.Across row -10% to 20 % higher corn yields than the random and with-row leaf orientation.Sujatha et al. (2004)50% less light reached the ground between rows of horizontal leaf hybrid compared with upright leaf in both years.
23 ConclusionsPlacement and arrangement of corn seed can influence rate of emergence and leaf orientation.At V10 fixed seed planting intercept more light than random seed planting.At R1upright seed position intercept more light than random.Effect of seed orientation on light interception was independent of plant population and hybrid.Difference in light interception decreases with maturity.Controlled leaf geometry could facilitate planting higher populations with the potential for increasing grain yield or permit the preservation of yields with reduced plant populations.